Title : An unusual presentation of Creutzfeldt-Jakob Disease as a stroke mimic
Abstract:
A 56-year-old female patient presented with a five-week history of unsteadiness, progressively worsening double vision, unsteady handwriting and subtle cognitive decline with mild forgetfulness. She also had an intermittent dry cough.
A CT head scan was unremarkable. However, the subsequent MRI revealed bilateral diffusion restriction in the basal ganglia and thalami, more pronounced on the left. This raised suspicion for prion disease and prompted consideration of Creutzfeldt-Jakob disease (CJD) in the differential diagnosis. A cerebrospinal fluid (CSF) RT-QuIC test confirmed the diagnosis of CJD.
Her past medical history was significant only for hypertension. Extensive investigations, including neuroimmunology screening, serum immunoglobulin levels, and urine drug screening, were negative. Family history was non-significant for neurodegenerative disease.
On cognitive assessment, the patient scored 27/30 on the Mini-Mental State Examination (MMSE) and 16/20 on the MRC cognitive scale. Neurological examination revealed saccadic intrusions during smooth pursuit, which were hypometric in all directions. The patient had horizontal diplopia in all directions of gaze, more pronounced when looking to the left. This did not resolve with monocular occlusion or head tilt.
Her speech was slightly tremulous, although there was no evidence of dysarthria. Muscle tone was mildly increased in the right leg, and muscle strength was preserved throughout. Mild dysmetria was noted on the finger-to-nose test on the right side, with otherwise intact coordination. Ankle reflexes were absent, and all other reflexes were present.
The patient was unable to perform tandem walking and had an ataxic gait and required support from one person to mobilise. The patient was reviewed by the teams at the National Prion Clinic and the National CJD Surveillance Unit, both of whom confirmed the diagnosis based on her clinical features, MRI head and CSF RT-QuIC.
Following confirmation of diagnosis, the patient received community-based rehabilitation alongside palliative support and was subsequently discharged home.
This case report illustrates an atypical presentation of CJD. Patients presenting with cerebellar signs with other atypical features should have CJD considered in their differential diagnoses. This case also highlights the challenges in the early diagnosis of CJD, especially when initial symptoms are subtle. Advanced neuroimaging and specialized diagnostic tools such as the RT-QuIC assay are essential for accurate and timely diagnosis.
